Background: Abundance calculations of $p$ nuclei require knowledge of cross sections for numerous nuclear reactions. Since measuring all relevant cross sections is unfeasible, these calculations typically rely on predictions from Hauser-Feshbach theory. The accuracy of these predictions depends on the reliability of key nuclear models: the optical model potential (OMP), nuclear level density (NLD), and $\gamma$-ray strength function ($\gamma \mathrm{SF}$).

Purpose: This study presents cross-section measurements for the ${}^{63}\mathrm{Cu}(\alpha ,\gamma ){}^{67}\mathrm{Ga}$ reaction at center-of-mass energies between $\approx 4.9$ and 8 MeV, which fully cover the Gamow window relevant to $p$-process nucleosynthesis, for typical temperatures between $1.8\times {10}^9\text{and}3.3\times {10}^9\mathrm{K}$.

Method: Experiments were performed at the Dynamitron Tandem Laboratory of Ruhr-University Bochum, Germany, using a $12\times 12\text{-in.}$ NaI(Tl) scintillator detector and the $4\pi \gamma$-summing technique.

Results: The measured ${}^{63}\mathrm{Cu}(\alpha ,\gamma ){}^{67}\mathrm{Ga}$ cross sections show very good agreement with existing data. Results were compared with calculations performed with the talys (version 2.0) nuclear reaction code.

Conclusions: The cross sections measured for the ${}^{63}\mathrm{Cu}(\alpha ,\gamma ){}^{67}\mathrm{Ga}$ reaction are in overall good agreement with previously reported cross sections measured through the activation technique. Despite limited independent data on NLDs and $\gamma \mathrm{SF}$ and the inability to isolate the $\alpha$-particle nucleus OMP, the dispersion semimicroscopic model of Demetriou et al. [P. Demetriou, C. Grama, and S. Goriely, Nucl. Phys. A 718, 510 (2003)] satisfactorily reproduces the experimental cross sections and $S$ factors without further tuning.

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• H & He induced nuclear reactions
• Nuclear astrophysics
• Radiative capture
• S-factor
• Total cross sections
• 59 ≤ A ≤ 89